Process of manufacturing pulp or paper



June 30, 1925. 1,543,663

L. M. BOOTH PRocEss oF MANUFACTURING PULP 0R PAPER Filed Feb. 14. 41923 /NI/ENTOR /l TTORNEY Patented June 30, 1925.

LEVIS MILLER BOOTH, 0F I-LAIN FIELD, NEW JERSEY.

:PROCESS 0F MANUFACTURING PULP 0R PAPER.

Application led February 14, 1923. Serial No. 618,965.

To all whom t may concern.'

Be i known that I, Lavis MILLER Booa'u, a citizen of the United States, residing at Plainfield, inthe' county of Union, State ot New Jersey, have invented certain new and useful Improvements in Processes of Manufacturing Pulp or Paper.

This inventlon relates to the process of manufacturing pulp or paper on a Fourdrinier or other paper machine where the stock is suspended in water and is applied to a screen. By the rocess heretofore in use a substantiall ortlon of the fibre and loading material 1f any of the latter was used, together with nearly all of the water which. passes through the screen was either wasted or went to a save-all or a sedimentation pulp saver. `The sedimentation pulp saving equipment heretofore employed was of low eiici'enc for `many types of white water in that 1t permitted a considerable portion of the pulp to flow cti to waste along 'with theV partly clarified water, and the pulp which settled at the bottom of the tank became partially elted on the bottom -of th'e tank with the result that the thickened pulp etiuent drawn from the bottom vof the tank was not of uniform consistency and therefore could not be advantageously returned directly to the paper machine, as isv immediate reuse on the paper machine.

The lirst step in my present process consists in applying to the white water from lthe paper machine two or more chemical reagents which will produce a i'locculent .precipitate and therefore assist in the sedimentation, as is described in my. said Letters Patent. Sulphate of aluminum and sodium carbonate are among the reagents suitable for this purpose.

A. The second step consists in delivering the white water to which such chemical treatment has been. o`r is then applied to the lower. portion of a sedimentation tank whlch is equipped with a Slowly movin" agitator travellng near the bottom of sucllI tank and at such speed that there will be no appreciable interference with the sedimentation of the pulp or the clarity of the water in gie upper portion of the sedimentation tan Third, after the pulp has accumulated by sedimentation in the lower portion of the ally less than onev hour from the starting of the paper machine, the outlet valve located paper making materials in the white water will be withdrawn through the thickenedpulp outlet from the lower portion of the tank in condition 'to be supplied to the paper machine.

The. application of a suitable coagulantto the white water together with the continually slow moving agitator has the eli'ect of maintaining a high degree of uniformity in the consistency of the paper making materials. Preferably, the speed of the agitator is about three feet per minute and when the agitator is moved at this speed and the valve controlling the outlet near the bottom of the tank properly regulated, the thickened pulp flowing from the tank is suitable for useon the paper machine.

From a higher point'in thetank, usually four or more feet above the bottom, water for the beaters or forother uses is withdrawn from the pulp saver sedimentation tank from time to time, as required. In practice eight or nine per cent-of the pulp contained in `the white water is drawn from the upper. level just referred to. The surplus of water, if any, may be drawn from near the top of the tank. Due to thein- Huence of gravityassisted by the chemical coagulation a proximately ninety per cent of the pulp the clarified eiliuent taken from the top of the tank usually contains only one to two alls to the lower portion of l thesedimentation tank. The result is that 65 pulp saver tank for a period which is usu- A throughout the various views.

- municating with t In tne accompanying drawing, 1 designates the sedimentation tank which is preferably ten feet or more in depth, 2 the slow moving agitator, 3 ay pipe communicating with the tank near .the bottom thereof-.

through which the thickened pul .is discharged, 4 a valve serving to cut o or regulate the flow vof thickened pulp from the tank through the pipe 3, 5 is a" pipe come tank preferably four or'more feet from the bottom thereof, 6 is a valve adapted to cut off or regulate the flow of liquid from the tank through the pipe 5, 7 1s a circumferential launder into which the surplus water which usually contains from one to two per cent of the pulp contained in the white water supplied to the tank isy discharged from the tank 1 through the pi 8, for conveying said water to any desire point in the paper mill or elsewhere, 9 is the inlet pipe by which white water is supplied to the tank 1. The white .water from the pipe 9 is discharged into the centrally located box 10, the open and lower end vof which is located, as shown, some distance above the bottom of the tank 1 and the agitator 2, the dimensions of the box 10 being-such that the flow of white water is not sufficiently rapid to cause disturbing eddies or currents which will interfere substantially with the sedimentation in the tank 1. v

Claims. t

ll. The process of manufacturing pulp or 'paper consisting of reclaiming for reuse the solid particles in the white water by the addition thereto of such rea ents as will assist by coagulation in the sedimentation of the solid particles, permitting the solid particles to settle by sedimentation to the bot:k tom of a sedimentation tank, gently agitat; ing the liquid in the sedimentation tank b means of a `slowly traveling agitator trave ing near the bottom of the sedimentation tank, "discharging the thickened pulp from the lower portion of the tank and the sur-A plus liquid from a plurality of higher levels as required.

- 2. The process of manufacturing pulp or paper consisting of reclaiming for reuse the solid particles in the white water by the addition thereto of such reagents as will assist by coagulation in 'the sedimentation of the solid particles, permitting the solid articles to settle by sedimentation to the ottom of a sedimentation tank, gently agitating the li uid in the sedimentation tank by means o a slowly traveling .agitator traveling near the bottom of the sedimentation tank and discharging the thickened pulp from the lower ortion of the sedimentation tank in con ition to be added to the pulp supplied to the paper machine and discharging the surplus liquid from -said tank at a plurality of higher levels as required.

3. The process of manufacturing pulp or paper consisting of reclaiming for reuse the solid particles 1n the white Water by addition t ereto of such reagents as will assist by coagulation in the sedimentation of the solid particles, permitting the solid particles to settle by sedimentation to the bottom of a sedimentation tank, gently agitating the liquid in the sedimentation tank by means of a slowly travelin agitatortraveling near the bottom of t e sedimentation tank, discharging the thickened pulp from the lower portion of the sedimentation tank and so regulating the rate of discharge that the thickened pulp discharged from said tank will be in condition to be added to the pulp supplied to the paper machine and discharging the surplus liquid from said tank at a plurality of higher levels as required.

LEVIS MILLER BOOTH. 

